I just received a Garmin 240 fishfinder as a gift for a favor I did. I think my brother paid around $85 for it on clearance brand new in a box. The unit came with a 20deg trolling motor mount sensor that has depth & temp. It also came with a transom speed sensor. The unit has a small amber LCD display.

Has anyone ever used one of these? What did you think of them?

Any tips on using it?

I have 3 Garmin units, great working sonar for the price.

Just read the owner's manual, you'll pick up on operation of the unit pretty quick.

Thanks for the advice. I've spent quite a bit of time reading the book. It also comes with a demo program so I have experimented quite a bit with the settings, display etc. I'm as ready as can be for never having owned one before. I just need a break in the weather to get it on the lake.  They can keep this 100 deg crap. On vacation next week so I've got fingers crossed for some fishing time.